Sophisticated ‘tickle’-style defences of Evidential Decision Theory take your motivational state to screen off your act from any state that is causally independent of it, thus ensuring that EDT and CDT converge. That leads to unacceptable instability in cases in which the correct action is obvious. We need a more liberal conception of what the agent controls. It follows that an ordinary deliberator should sometimes consider the past and not only the future to be subject to her present choice.

Whereas The Stag Hunt and the Evolution of Social Structure supplements Evolution of the Social Contract by examining some of the earlier work’s strategic problems in a local interaction setting, no equivalent supplement exists for The Dynamics of Rational Deliberation . In this article, I develop a general framework for modeling the dynamics of rational deliberation in a local interaction setting. In doing so, I show that when local interactions are permitted, three interesting phenomena occur: (a) the attracting deliberative equilibria (...) may fail to agree with any of the Nash equilibria of the underlying game, (b) deliberative dynamics which converged to the same deliberative outcome in The Dynamics of Rational Deliberation may lead to different deliberative outcomes here, and (c) Bayesian deliberation seems to be more likely to avoid nonstandard deliberative outcomes, contrary to the result reported in The Dynamics of Rational Deliberation , which argued in favour of the Brown–von Neumann–Nash dynamics. (shrink)

Imagine a group that faces a decision problem but does not agree on which decision procedure is appropriate. In that case, can a decision be reached that respects the procedural concerns of the group? There is a sense in which legitimate decisions are possible even if people disagree on which procedure to use. I propose to decide in favour of an option which maximizes the number of persons whose judged-right procedure happens to entail this decision given the profile. This decision (...) rule is based not only on a profile in the standard sense, but in addition on a profile of judged-right procedures. To justify this decision rule, I present a set of simple axioms leading to it as the only solution. (shrink)

According to standard rational choice theory, as commonly used in political science and economics, an agent’s fundamental preferences are exogenously …xed, and any preference change over decision options is due to Bayesian information learning. Although elegant and parsimonious, this model fails to account for preference change driven by experiences or psychological changes distinct from information learning. We develop a model of non-informational preference change. Alternatives are modelled as points in some multidimensional space, only some of whose dimensions play a role (...) in shaping the agent’s preferences. Any change in these ‘motivationally salient’ dimensions can change the agent’s preferences. How it does so is described by a new representation theorem. Our model not only captures a wide range of frequently observed phenomena, but also generalizes some standard representations of preferences in political science and economics. (shrink)

When decision makers have more to gain than to lose by changing their minds, and that is the only relevant fact, they thereby have a reason to change their minds. While this is sage advice, it is silent on when one stands more to gain than to lose. The two envelope paradox provides a case where the appearance of advantage in changing your mind is resilient despite being a chimera. Setups that are unproblematically modeled by decision tables that are used (...) in the formulation of the two envelope paradox are described, and variations on them are stipulated. The problems posed by the paradoxical modeling are then contrasted with the variations. The paper concludes with a brief explanation of why the paradoxical modeling does not gain support from the fact that one envelope has twice the amount that is in the other. (shrink)

In everyday life people frequently recognize that a person at a time may be more or less strongly motivated to carry out an intentional action and that “trying harder” frequently affects the successful completion of an intentional action. In “Rational Choice and Action Omnipotence,” John Pollock provides an original account of rational choice in which “trying to do an action” is a basic factor. This paper argues that Pollock’s “expected-utility optimality prescription” is deficient because it lacks a parameter for intensity (...) of trying. The paper also indicates specific ways in which this deficiency could be corrected. (shrink)

In the standard money pump, an agent with cyclical preferences can avoid exploitation if he shows foresight and solves his sequential decision problem using backward induction (BI). This way out is foreclosed in a modified money pump, which has been presented in Rabinowicz (2000). There, BI will lead the agent to behave in a self-defeating way. The present paper describes another sequential decision problem of this kind, the Centipede for an Intransitive Preferrer, which in some respects is even more striking (...) than the modified pump. In the new problem, the BI reasoning that implies self-defeating behavior does not rest on the controversial robustness assumption concerning beliefs in one's future rationality. This strengthens the claim that foresight cannot save the intransitive preferrer from a self-defeating course of action. (shrink)

An agent who violates independence can avoid dynamic inconsistency in sequential choice if he is sophisticated enough to make use of backward induction in planning. However, Seidenfeld has demonstrated that such a sophisticated agent with dependent preferences is bound to violate the principle of dynamic substitution, according to which admissibility of a plan is preserved under substitution of indifferent options at various choice nodes in the decision tree. Since Seidenfeld considers dynamic substitution to be a coherence condition on dynamic choice, (...) he concludes that sophistication cannot save a violator of independence from incoherence. In response to McClennen’s objection that relying on dynamic substitution when independence is at stake must be question-begging, Seidenfeld undertakes to prove that dynamic substitution follows from the principle of backward induction alone, provided we assume that the agent’s admissible choices from different sets of feasible plans are all based on a fixed underlying preference ordering of plans. This paper shows that Seidenfeld's proof fails: depending on the interpretation, it is either invalid or based on an unacceptable assumption. (shrink)

Many of the world's problems--severe poverty and starvation, global warming, religious war, oppressive and tyrannical regimes--are large, well beyond what any ordinary person might have a significant impact upon. We are at most in a position to make small contributions. This fact is behind a seductive argument: there is nothing we can do about the large problems; since we cannot do anything about the large problems, it is not true that we ought to do anything; therefore, we can, in good (...) conscience, decline to contribute. There may be something to this argument, but we should not make too much of it. What I shall argue is that much depends on the details, that sometimes small contributions, even when there is little prospect of solving the large problem, may be warranted. Worries about the smallness of our contribution do not undermine all reasons for making the small contributions. (shrink)

The authors argue, against Frank Jackson, that weakness (and strength) of will involves higher-order mental states. The authors hold that this is compatible with a decision-theoretic belief-desire psychology of human action.

A recurring objection confronting utilitarianism is that its dictates require information that lies beyond the bounds of human epistemic wherewithal. Utilitarians require reliable knowledge of the social consequences of various policies, and of people’s preferences and utilities. Agreeing partway with the sceptics, I concur that the general rules-of-thumb offered by social science do not provide sufficient justification for the utilitarian legislator to rationally recommend a particular political regime, such as liberalism. Actual data about human preference-structures and utilities is required to (...) bridge this evidentiary gap. I offer two arguments to support the availability of such information. First, I contend that ordinary human beings have a clear method of epistemic access to reliable information about commensurable preference-structures. Second, in an attempt to shift the onus of philosophic argument, I show that the utilitarian legislator’s requirements do not differ in kind from those implicitly called upon by the sceptical deontic liberal. (shrink)

In this paper we explore the connections between ethics and decision theory. In particular, we consider the question of whether decision theory carries with it a bias towards consequentialist ethical theories. We argue that there are plausible versions of the other ethical theories that can be accommodated by "standard" decision theory, but there are also variations of these ethical theories that are less easily accommodated. So while "standard" decision theory is not exclusively consequentialist, it is not necessarily ethically neutral. Moreover, (...) even if our decision-theoretic models get the right answers vis-à-vis morally correct action, the question remains as to whether the motivation for the non-consequentialist theories and the psychological processes of the agents who subscribe to those ethical theories are lost or poorly represented in the resulting models. (shrink)

On the face of it, ethics and decision theory give quite different advice about what the best course of action is in a given situation. In this paper we examine this alleged conflict in the realm of environmental decision-making. We focus on a couple of places where ethics and decision theory might be thought to be offering conflicting advice: environmental triage and carbon trading. We argue that the conflict can be seen as conflicts about other things (like appropriate temporal scales (...) for value assignments, idealisations of the decision situation, whether the conservation budget really is fixed and the like). The good news is that there is no conflict between decision theory and environmental ethics. The bad news is that a great deal of environmental decision modelling may be rather simple minded, in that it does not fully incorporate some of these broader issues about temporal scales and the dynamics of many of the decision situations. (shrink)

In the last half century, decision theory has had a deep influence on moral theory. Its impact has largely been beneficial. However, it has also given rise to some problems, two of which are discussed here. First, issues such as risk-taking and risk imposition have been left out of ethics since they are believed to belong to decision theory, and consequently the ethical aspects of these issues have not been treated in either discipline. Secondly, ethics has adopted the decision-theoretical idea (...) that action-guidance has to be based on cause–effect or means–ends relationships between an individual action and its possible outcomes. This is problematic since the morally relevant connections between an action and future events are not fully covered by such relationships. In response to the first problem it is proposed that moral theory should deal directly and extensively with issues such as risk-taking and risk imposition, thereby intruding unabashedly into the traditional territory of decision theory. As a partial response to the second problem it is proposed that moral theorizing should release itself from the decision-theoretical requirement that the moral status of an action has to be derivable from the consequences (or other properties) that are assignable to that action alone. In particular, the effects that an action can have in combination with other actions by the same or other agents are valid arguments in an action-guiding moral discourse, even if its contribution to these combined consequences cannot be isolated and evaluated separately. (shrink)

The purpose of this paper is to show how some of the controversial questions concerning utilitarianism can be clarified by the modelling techniques and the other analytical tools of decision theory (and, sometimes, of game theory). It is suggested that the moral rules of utilitarian ethics have a logical status similar to that of the normative rules (theorems) of such formal normative disciplines as decision theory and game theory.The paper argues that social utility should be defined, not in hedonistic or (...) in ideal-utilitarian terms, but rather in terms of individual preferences, in accordance with the author's equiprobability model of moral value judgments. (shrink)

If it can be agreed that health care resources are finite, it follows that choices between competing needs must be made. Cost utility analysis is an application of decision theory which has been proposed as a strategy for making difficult social decisions about health resource allocations. This method is heavily dependent upon the measurement of social utilities for various health outcomes. Recent work in cognitive psychology suggests that there are important sources of distortion in such measurement. Ethical implications of application (...) of cost utility analysis to health resource allocations are discussed. (shrink)

We are often uncertain how to behave morally in complex situations. In this controversial study, Ted Lockhart contends that moral philosophy has failed to address how we make such moral decisions. Adapting decision theory to the task of decision-making under moral uncertainly, he proposes that we should not always act how we feel we ought to act, and that sometimes we should act against what we feel to be morally right. Lockhart also discusses abortion extensively and proposes new ways to (...) deal with the ethical and moral issues which surround it. (shrink)

Introduction: The Relevance of Rational Decision Theory for Ethics Content Type Journal Article DOI 10.1007/s10677-010-9228-9 Authors Christoph Lumer, Università degli Studi di Siena, Dipartimento di Filosofia, Via Roma, 47, 53100 Siena, Italy Journal Ethical Theory and Moral Practice Online ISSN 1572-8447 Print ISSN 1386-2820 Journal Volume Volume 13 Journal Issue Volume 13, Number 5.

Being a formal and general as well as the most widely accepted approach to practical rationality, rational decision theory should be crucial for justifying rational morals. In particular, acting morally should also (nearly always) be rational in decision theoretic terms. After defending this thesis, in the critical part of the paper two strategies to develop morals following this insight are criticized: game theoretical ethics of cooperation and ethical intuitionism. The central structural objections to ethics of cooperation are that they too (...) directly aim at the rationality of moral action and that they to do not encompass moral values or a moral desirability function. The constructive half of the paper takes up these criticisms by developing a two-part strategy to bring rationality and morals in line. The first part is to define ‘moral desirability’. This is done, using multi-attribute utility theory, by equating several adequate components of an individual’s comprehensive (rational) utility function with the moral desirability function. The second part is to introduce mechanisms, institutions, in particular socially valid moral norms, that provide further motivation for acting in accordance with morals. (shrink)

In many forms of severe acute brain injury there is an early phase when prognosis is uncertain, followed later by physiological recovery and the possibility of more certain predictions of future impairment. There may be a window of opportunity for withdrawal of life support early, but if decisions are delayed there is the risk that the patient will survive with severe impairment. In this paper I focus on the example of neonatal encephalopathy and the question of the timing of prognostic (...) tests and decisions to continue or to withdraw life-sustaining treatment. Should testing be performed early or later; and how should parents decide what to do given the conflicting values at stake? I apply decision theory to the problem, using sensitivity analysis to assess how different features of the tests or different values would affect a decision to perform early or late prognostic testing. I draw some general conclusions from this model for decisions about the timing of testing in neonatal encephalopathy. Finally I consider possible solutions to the problem posed by the window of opportunity. Decision theory highlights the costs of uncertainty. This may prompt further research into improving prognostic tests. But it may also prompt us to reconsider our current attitudes towards the palliative care of newborn infants predicted to be severely impaired. (shrink)

This paper is partly a tribute to Richard Jeffrey, partly a reflection on some of his writings, The Logic of Decision in particular. I begin with a brief biography and some fond reminiscences of Dick. I turn to some of the key tenets of his version of Bayesianism. All of these tenets are deployed in my discussion of his response to the St. Petersburg paradox, a notorious problem for decision theory that involves a game of infinite expectation. Prompted by that (...) paradox, I conclude with some suggestions of avenues for future research. (shrink)

We pose and resolve several vexing decision theoretic puzzles. Some are variants of existing puzzles, such as ‘Trumped’ (Arntzenius and McCarthy 1997), ‘Rouble trouble’ (Arntzenius and Barrett 1999), ‘The airtight Dutch book’ (McGee 1999), and ‘The two envelopes puzzle’ (Broome 1999). Others are new. A unified resolution of the puzzles shows that Dutch book arguments have no force in infinite cases. It thereby provides evidence that reasonable utility functions may be unbounded and that reasonable credence functions need not be countably (...) additive. The resolution also shows that when infinitely many decisions are involved, the difference between making the decisions simultaneously and making them sequentially can be the difference between riches and ruin. Finally, the resolution reveals a new way in which the ability to make binding commitments can save perfectly rational agents from sure losses. (shrink)

In their paper, “Vexing Expectations,” Nover and Hájek (2004) present an allegedly paradoxical betting scenario which they call the Pasadena Game (PG). They argue that the silence of standard decision theory concerning the value of playing PG poses a serious problem. This paper provides a threefold response. First, I argue that the real problem is not that decision theory is “silent” concerning PG, but that it delivers multiple conflicting verdicts. Second, I offer a diagnosis of the problem based on the (...) insight that standard decision theory is, rightly, sensitive to order. Third, I describe a new betting scenario—the Alternating St. Petersburg Game—which is genuinely paradoxical. Standard decision theory is silent on the value of playing this game even if restrictions are placed on the order in which the various alternative payoffs are summed. †To contact the author, please write to: Department of Philosophy, Swarthmore College, Swarthmore, PA 19081; e-mail: abaker1@swarthmore.edu. (shrink)

Pulier (2000, Theory and Decision 49: 291) and Machina (2000, Theory and Decision 49: 293) seek to dissolve the Barrett–Arntzenius infinite decision puzzle (1999, Theory and Decision 46: 101). The proposed dissolutions, however, are based on misunderstandings concerning how the puzzle works and the nature of supertasks more generally. We will describe the puzzle in a simplified form, address the recent misunderstandings, and describe possible morals for decision theory.

We tell a story where an agent who chooses in such a way as to make the greatest possible profit on each of an infinite series of transactions ends up worse off than an agent who chooses in such a way as to make the least possible profit on each transaction. That is, contrary to what one might suppose, it is not necessarily rational always to choose the option that yields the greatest possible profit on each transaction.

Games such as the St. Petersburg game present serious problems for decision theory.1 The St. Petersburg game invokes an unbounded utility function to produce an infinite expectation for playing the game. The problem is usually presented as a clash between decision theory and intuition: most people are not prepared to pay a large finite sum to buy into this game, yet this is precisely what decision theory suggests we ought to do. But there is another problem associated with the St. (...) Petersburg game. The problem is that standard decision theory counsels us to be indifferent between any two actions that have infinite expected utility. So, for example, consider the decision problem of whether to play the St. Petersburg game or a game where every payoff is $1 higher. Let’s call this second game the Petrograd game (it’s the same as St. Petersburg but with a bit of twentieth century inflation). Standard decision theory is indifferent between these two options. Indeed, it might be argued that any intuition that the Petrograd game is better than the St. Petersburg game is a result of misguided and na¨ıve intuitions about infinity.2 But this argument against the intuition in question is misguided. The Petrograd game is clearly better than the St. Petersburg game. And what is more, there is no confusion about infinity involved in thinking this. When the series of coin tosses comes to an end (and it comes to an end with probability 1), no matter how many tails precede the first head, the payoff for the Petrograd game is one dollar higher than the St. Petersburg game. Whatever the outcome, you are better off playing the Petrograd game. Infinity has nothing to do with it. Indeed, a straightforward application of dominance reasoning backs up this line of reasoning.3 Standard decision theory. (shrink)

The Pasadena paradox presents a serious challenge for decision theory. The paradox arises from a game that has well-defined probabilities and utilities for each outcome, yet, apparently, does not have a well-defined expectation. In this paper, I argue that this paradox highlights a limitation of standard decision theory. This limitation can be (largely) overcome by embracing dominance reasoning and, in particular, by recognising that dominance reasoning can deliver the correct results in situations where standard decision theory fails. This, in turn, (...) pushes us towards pluralism about decision rules. (shrink)

Fine has shown that assigning any value to the Pasadena game is consistent with a certain standard set of axioms for decision theory. However, I suggest that it might be reasonable to believe that the value of an individual game is constrained by the long-run payout of repeated plays of the game. Although there is no value that repeated plays of the Pasadena game converges to in the standard strong sense, I show that there is a weaker sort of convergence (...) it exhibits, and use this to define a notion of ‘weak expectation’ that can give values to the Pasadena game and many others, though not to all games that fail to have a strong expectation in the standard sense. CiteULike Connotea Del.icio.us What's this? (shrink)

By recourse to the fundamentals of preference orderings and their numerical representations through linear utility, we address certain questions raised in Nover and Hájek 2004, Hájek and Nover 2006, and Colyvan 2006. In brief, the Pasadena and Altadena games are well-defined and can be assigned any finite utility values while remaining consistent with preferences between those games having well-defined finite expected value. This is also true for the St Petersburg game. Furthermore, the dominance claimed for the Altadena game over the (...) Pasadena game, and that would have been claimed for the St Petersburg game over the Altadena, can be contradicted without fear of inconsistency with the axioms of utility theory. However, insistence upon dominance can be made to yield a contradiction of the Archimedean axiom of utility theory. CiteULike Connotea Del.icio.us What's this? (shrink)

We introduce a St. Petersburg-like game, which we call the ‘Pasadena game’, in which we toss a coin until it lands heads for the first time. Your pay-offs grow without bound, and alternate in sign (rewards alternate with penalties). The expectation of the game is a conditionally convergent series. As such, its terms can be rearranged to yield any sum whatsoever, including positive infinity and negative infinity. Thus, we can apparently make the game seem as desirable or undesirable as we (...) want, simply by reordering the pay-off table, yet the game remains unchanged throughout. Formally speaking, the expectation does not exist; but we contend that this presents a.. (shrink)

This paper revisits the Pasadena game (Nover and Háyek 2004), a St Petersburg-like game whose expectation is undefined. We discuss serveral respects in which the Pasadena game is even more troublesome for decision theory than the St Petersburg game. Colyvan (2006) argues that the decision problem of whether or not to play the Pasadena game is ‘ill-posed’. He goes on to advocate a ‘pluralism’ regarding decision rules, which embraces dominance reasoning as well as maximizing expected utility. We rebut Colyvan’s argument, (...) offering several considerations in favour of the Pasadena decision problem being well posed. To be sure, current decision theory, which is underpinned by various preference axioms, leaves indeterminate how one should value the Pasadena game. But we suggest that determinacy might be achieved by adding further preference axioms. We conclude by opening the door to a far greater plurality of decision rules. We suggest how the goal of unifying these rules might guide future research. (shrink)

We argue that indeterminate probabilities are not only rationally permissible for a Bayesian agent, but they may even be rationally required . Our first argument begins by assuming a version of interpretivism: your mental state is the set of probability and utility functions that rationalize your behavioral dispositions as well as possible. This set may consist of multiple probability functions. Then according to interpretivism, this makes it the case that your credal state is indeterminate. Our second argument begins with our (...) describing a world that plausibly has indeterminate chances. Rationality requires a certain alignment of your credences with corresponding hypotheses about the chances. Thus, if you hypothesize the chances to be indeterminate, your will inherit their indeterminacy in your corresponding credences. Our third argument is motivated by a dilemma. Epistemic rationality requires you to stay open-minded about contingent matters about which your evidence has not definitively legislated. Practical rationality requires you to be able to act decisively at least sometimes. These requirements can conflict with each other-for thanks to your open-mindedness, some of your options may have undefined expected utility, and if you are choosing among them, decision theory has no advice to give you. Such an option is playing Nover and Hájek’s Pasadena Game , and indeed any option for which there is a positive probability of playing the Pasadena Game. You can serve both masters, epistemic rationality and practical rationality, with an indeterminate credence to the prospect of playing the Pasadena game. You serve epistemic rationality by making your upper probability positive-it ensures that you are open-minded. You serve practical rationality by making your lower probability 0-it provides guidance to your decision-making. No sharp credence could do both. (shrink)

The Barrett and Arntzenius (1999) decision paradox involves unbounded wealth, the relationship between period-wise and sequence-wise dominance, and an infinite-period split-minute setting. A version of their paradox involving bounded (in fact, constant) wealth decisions is presented, along with a version involving no decisions at all. The common source of paradox in Barrett–Arntzenius and these other examples is the indeterminacy of their infinite-period split-minute setting.

In “Bayesianism, Infinite Decisions, and Binding”, Arntzenius et al. (Mind 113:251–283, 2004 ) present cases in which agents who cannot bind themselves are driven by standard decision theory to choose sequences of actions with disastrous consequences. They defend standard decision theory by arguing that if a decision rule leads agents to disaster only when they cannot bind themselves, this should not be taken to be a mark against the decision rule. I show that this claim has surprising implications for a (...) number of other debates in decision theory. I then assess the plausibility of this claim, and suggest that it should be rejected. (shrink)

Clark and Shackel have recently argued that previous attempts to resolve the two-envelope paradox fail, and that we must look to symmetries of the relevant expected-value calculations for a solution. Clark and Shackel also argue for a novel solution to the peeking case, a variant of the two-envelope scenario in which you are allowed to look in your envelope before deciding whether or not to swap. Whatever the merits of these solutions, they go beyond accepted decision theory, even contradicting it (...) in the peeking case. Thus if we are to take their solutions seriously, we must understand Clark and Shackel to be proposing a revision of standard decision theory. Understood as such, we will argue, their proposal is both implausible and unnecessary. (shrink)

Common probabilistic fallacies and putative paradoxes are surveyed, including those arising from distribution repartitioning, from the reordering of expectation series, and from misconceptions regarding expected and almost certain gains in games of chance. Conditions are given for such games to be well-posed. By way of example, Bernoulli's "Petersburg Paradox" and Hacking's "Strange Expectations" are discussed and the latter are resolved. Feller's generalized "fair price, in the classical sense" is critically reviewed.

In our (2004), we introduced two games in the spirit of the St. Petersburg game, the Pasadena and Altadena games. As these latter games lack an expectation, we argued that they pose a paradox for decision theory. Terrence Fine has shown that any finite valuations for the Pasadena, Altadena, and St. Petersburg games are consistent with the standard decision­theoretic axioms. In particular, one can value the Pasadena game above the other two, a result that conflicts with both our intuitions and (...) dominance reasoning. We argue that this result, far from resolving the Pasadena paradox, should serve as a reductio of the standard theory, and we consequently make a plea for new axioms for a revised theory. We also discuss a proposal by Kenny Easwaran that a gamble should be valued according to its ‘weak expectation’, a generalization of the usual notion of expectation. (shrink)

Petersburg-like game, which we call the ‘Pasadena game’, in which we toss a coin until it lands heads for the first time. Your pay-offs grow without bound, and alternate in sign (rewards alternate with penalties). The expectation of the game is a conditionally convergent series. As such, its terms can be rearranged to yield any sum whatsoever, including positive infinity and negative infinity. Thus, we can apparently make the game seem as desirable or undesirable as we want, simply by reordering (...) the pay-off table, yet the game remains unchanged throughout. Formally speaking, the expectation does not exist; but we contend that this presents a serious problem for decision theory, since it goes silent when we want it to speak. We argue that the Pasadena game is more paradoxical than the St. Petersburg game in several respects. We give a brief review of the relevant mathematics of infinite series. We then consider and rebut a number of replies to our paradox: that there is a privileged ordering to the expectation series; that decision theory should be restricted to finite state spaces; and that it should be restricted to bounded utility functions. We conclude that the paradox remains live. (shrink)

The recently proposed ``infinite decision puzzle'' is based on incorrect mathematics.

The two envelopes problem has generated a significant number of publications (I have benefitted from reading many of them, only some of which I cite; see the epilogue for a historical note). Part of my purpose here is to provide a review of previous results (with somewhat simpler demonstrations). In addition, I hope to clear up what I see as some misconceptions concerning the problem. Within a countably additive probability framework, the problem illustrates a breakdown of dominance with respect to (...) infinite partitions in circumstances of infinite expected utility. Within a probability framework that is only finitely additive, there are failures of dominance with respect to infinite partitions in circumstances of bounded utility with finitely many consequences (see the epilogue). (shrink)

When real-valued utilities for outcomes are bounded, or when all variables are simple, it is consistent with expected utility to have preferences defined over probability distributions or lotteries. That is, under such circumstances two variables with a common probability distribution over outcomes – equivalent variables – occupy the same place in a preference ordering. However, if strict preference respects uniform, strict dominance in outcomes between variables, and if indifference between two variables entails indifference between their difference and the status quo, (...) then preferences over rich sets of unbounded variables, such as variables used in the St. Petersburg paradox, cannot preserve indifference between all pairs of equivalent variables. In such circumstances, preference is not a function only of probability and utility for outcomes. Then the preference ordering is not defined in terms of lotteries. (shrink)

We extend de Finetti’s (1974) theory of coherence to apply also to unbounded random variables. We show that for random variables with mandated infinite prevision, such as for the St. Petersburg gamble, coherence precludes indifference between equivalent random quantities. That is, we demonstrate when the prevision of the difference between two such equivalent random variables must be positive. This result conflicts with the usual approach to theories of Subjective Expected Utility, where preference is defined over lotteries. In addition, we explore (...) similar results for unbounded variables when their previsions, though finite, exceed their expected values, as is permitted within de Finetti’s theory. In such cases, the decision maker’s coherent preferences over random quantities is not even a function of probability and utility. One upshot of these findings is to explain further the differences between Savage’s theory (1954), which requires bounded utility for non-simple acts, and de Finetti’s theory, which does not. And it raises a question whether there is a theory that fits between these two. (shrink)

A person who does not have good intellectual reasons for believing in God can, depending on his probabilities and values for consequences of believing, have good practical reasons. Pascalian wagers founded on a variety of possible probability/value profiles are examined from a Bayesian perspective central to which is the idea that states and options are pragmatically reasonable only if they maximize subjective expected value. Attention is paid to problems posed by representations of values by Cantorian infinities. An appendix attends to (...) Robinsonian hyperreals. Another appendix presents for comparison Newcomb's Problem and a problem in some ways like it suggested, I think, by ideas of John Calvin. (shrink)

Suppose that time is infinitely long towards the future, and that each feasible action produces a finite amount of utility at each time. Then, under appropriate conditions, each action produces an infinite amount of utility. Does this mean that utilitarianism lacks the resources to discriminate among such actions? Since each action produces the same infinite amount of utility, it seems that utilitarianism must judge all actions permissible, judge all actions impermissible, or remain completely silent. If the future is infinite, that (...) is, the prospects for utilitarianism look bleak. (shrink)

Where there are infinitely many possible basic states of the world, a standard probability function must assign zero probability to each state – since any finite probability would sum to over one. This generates problems for any decision theory that appeals to expected utility or related notions. For it leads to the view that a situation in which one wins a million dollars if any of a thousand of the equally probable states is realized has an expected value of zero (...) (since each such state has probability zero). But such a situation dominates the situation in which one wins nothing no matter what (which also has an expected value of zero), and so surely is more desirable. I formulate and defend some principles for evaluating options where standard probability functions cannot strictly represent probability – and in particular for where there is an infinitely spread, uniform distribution of probability. The principles appeal to standard probability functions, but overcome at least some of their limitations in such cases. (shrink)

Where there are infinitely many possible [equiprobable] basic states of the world, a standard probability function must assign zero probability to each state—since any finite probability would sum to over one. This generates problems for any decision theory that appeals to expected utility or related notions. For it leads to the view that a situation in which one wins a million dollars if any of a thousand of the equally probable states is realized has an expected value of zero (since (...) each such state has probability zero). But such a situation dominates the situation in which one wins nothing no matter what (which also has an expected value of zero), and so surely is more desirable. I formulate and defend some principles for evaluating options where standard probability functions cannot strictly represent probability—and in particular for where there is an infinitely spread, uniform distribution of probability. The principles appeal to standard probability functions, but overcome at least some of their limitations in such cases. (shrink)

In 1991 Mark Nelson argued that if time is infinitely long towards the future, then under certain easily met conditions traditional utilitarianism is unable to discriminate among actions. For under these conditions, each action produces the same infinite amount of utility, and thus it seems that utilitarianism must judge all actions permissible, judge all actions impermissible, or remain completely silent. In response to this criticism of utilitarianism, I argued that utilitarianism had the resources for dealing with at least some cases (...) of infinite utility. More specifically, I defended the following principle as being part of the "spirit" of traditional (total) utilitarianism: -/- PMU*: An action a1 has better consequences than an action a2 if and only if there is a time t such that for any later time t' the cumulative amount of utility produced by a1 up to t' is greater than that produced by action a2 up to t'. -/- For the usual finite cases, this principle agrees exactly with the standard approach of comparing totals. For infinite cases, however, it can distinguish among two actions each of which produces an infinite amount of utility. It says, for example, that an action that produces 2 units of utility at each time has better consequences than an action that produces 1 unit of utility at each time -- even though they both produce the same infinite amount of utility. Of course, cases where one action produces more utility than a second at each time are going to be rather rare. PMU* is not limited to such cases, however; it also has bite in cases such as the following: -/- Time a1: 1, 1, 1, 1, 2, 2, 2, 2, 2, ... a2: 3, 3, 3, 3, 1, 1, 1, 1, 1, ... -/- For although the cumulative utility of a1 up to and including the fourth time is only 4 utiles and a2's is 12, a1 starts catching up after that, ties a2 in the 12th time, and stays ahead after that. Thus, PMU* judges a1 as having better consequences than a2. I claimed that PMU* better captured the "spirit" of traditional utilitarianism than the usual sum total view -- on the grounds that almost anyone inclined to defend traditional utilitarianism would, upon reflection, want to hold, for example, that 2 utiles at every time is indeed better than 1 utile at each time. Two responses to my view have since been given in this journal. Luc Van Liederkerke has argued that PMU* violates an anonymity (neutrality, impartiality) condition that is central to utilitarianism. And James Cain has argued that PMU* is not person-centered, and that being so is central to utilitarianism. Here I will reply to the criticisms. Basically, I will acknowledge that each is right about an important point, but deny that this establishes that the core idea underlying PMU* is less plausible than the standard sum-ranking versions of utilitarianism. (shrink)

Traditional act utilitarianism judges an action permissible just in case it produces as much aggregate utility as any alternative. It is often supposed that utilitarianism faces a serious problem if the future is infinitely long. For in that case, actions may produce an infinite amount of utility. And if that is so for most actions, then utilitarianism, it appears, loses most of its power to discriminate among actions. For, if most actions produce an infinite amount of utility, then few actions (...) produce non-maximal utility, and so most actions are permissible.1 I will argue that potentially infinite futures create no major problems for utilitarianism. Utilitarianism has, I argue, the resources to distinguish among actions all of which produce infinite amounts of utility -- judging some permissible and some impermissible. For brevity of expression I will focus on act utilitarianism, but all the points apply equally well to many other traditional forms of utilitarianism. (shrink)

Puzzles can arise in ethical theory (as well as decision theory) when infinity is involved. The puzzles arise primarily in theories—such as consequentialist theories—that appeal to the value of actions or states of affairs. Section 1 addresses the question of whether one source of value (such as major aesthetic pleasures) can be infinitely more valuable than another (such as minor gustatory pleasures). An affirmative answer is given by appealing to the notion of lexicographic priority. Section 2 address the question of (...) what morality requires when there are an infinite number of feasible options and no option is maximally valuable? In such cases, it is suggested, morality can demand no more than that we “almost maximize” or (more weakly) that we “satisfice”. Section 3 addresses a puzzle that can arise when time is infinitely long. Is a state of affairs with two units of value at each time more valuable than a state of affairs with one unit at each time (even though both produce infinite amounts of value)? A plausible principle is introduced that answers affirmatively, but it faces certain problems. Section 4 addresses a puzzle that can arise when time is finite but infinitely divisible. (shrink)

Decision theory seems to offer a very attractive normative framework for individual and social choice under uncertainty. The decisionmaker should think of her choice situation, at any given moment, in terms of a set of possible outcomes, that is, specifications of the possible consequences of choice, described in light of the decisionmaker's goals; a set of possible actions; and a "state set" consisting of possible prior "states of the world." It is this framework for choice which provides the foundation for (...) expected utility theory, as demonstrated in the work of Leonard Savage. Problems arise, however, when the decisionmaker is boundedly rational: when the mental process of thinking about outcomes, actions, and states is itself expensive and time consuming. In the case of the unboundedly rational decisionmaker, decision theory enjoins her to employ maximally specific outcomes; to consider all possible actions; and to use a set of mutually exclusive and collective exhaustive states, each of which is sufficiently finely specified so that each action, together with each state, yields one and only one maximally specific outcome. In the case of the boundedly rational decisionmaker, this procedure is either infeasible or, if feasible, irrational. This paper presents the problem of bounded rationality. It surveys possible solutions, none of which are found to be attractive. And it concludes by discussing the difficulties that the problem of bounded rationality poses for the welfarist program for legal scholarship presented by Louis Kaplow and Steven Shavell in their book, Fairness versus Welfare. (shrink)

Behavioral science has long been puzzled by the experience of temptation, the resulting impulsiveness, and the variably successful control of this impulsiveness. In conventional theories, a governing faculty like the ego evaluates future choices consistently over time, discounting their value for delay exponentially, that is, by a constant rate; impulses arise when this ego is confronted by a conditioned appetite. Breakdown of Will (Ainslie 2001) presents evidence that contradicts this model. Both people and nonhuman animals spontaneously discount the value of (...) expected events in a curve where value is divided approximately by expected delay, a hyperbolic form that is more bowed than the rational, exponential curve. With hyperbolic discounting, options that pay off quickly will be temporarily preferred to richer but slower-paying alternatives, a phenomenon that, over periods from minutes to days, can account for impulsive behaviors, and over periods of fractional seconds can account for involuntary behaviors. Contradictory reward-getting processes can in effect bargain with each other, and stable preferences can be established by the perception of recurrent choices as test cases (precedents) in recurrent intertemporal prisoner's dilemmas. The resulting motivational pattern resembles traditional descriptions of the will, as well as of compulsive phenomena that can now be seen as side-effects of will: over-concern with precedent, intractable but circumscribed failures of self-control, a motivated (“dynamic”) unconscious, and an inability to exploit emotional rewards. Hyperbolic curves also suggest a means of reducing classical conditioning to motivated choice, the last necessary step for modeling many involuntary processes like emotion and appetite as reward-seeking behaviors; such modeling, in turn, provides a rationale for empathic reward and the “construction” of reality. Key Words: altruism; appetite; behavioral economics; classical conditioning; compulsions; dynamic inconsistency; emotions; empathy; freedom of will; hyperbolic discounting; impulsiveness; intertemporal bargaining; self-control; social construction; volition; weakness of will. (shrink)

The tension between rule and judgment is well known with respect to the meaning of substantive legal commands. The same conflict is present in fact finding. The law penetrates to virtually all aspects of human affairs; irtually any interaction can generate a legal conflict. Accurate fact finding about such disputes is a necessary condition for the appropriate application of substantive legal commands. Without accuracy in fact finding, the law is unpredictable, and thus individuals cannot efficiently accommodate their affairs to its (...) commands. The need for accuracy and predictability in legal fact finding has generated a search for formal tools to apply to the task. Among the tools that have been examined are Bayes' Theorem and expected utility theory (Bayesian or statistical decision theory). These tools do not map well onto trials, which in turn has generated an examination of alternative approaches, in particular the story model and the relative plausibility theory. This paper discusses these issues in turn. It elaborates the basic structure of trials in the American tradition; examines the uneasy relationship between trials and such formalisms as Bayes' Theorem and expected utility theory; and introduces the relative plausibility theory as an explanation of the nature of juridical proof. (shrink)

Daniel Ellsberg presented in Ellsberg (The Quarterly Journal of Economics 75:643–669, 1961) various examples questioning the thesis that decision making under uncertainty can be reduced to decision making under risk. These examples constitute one of the main challenges to the received view on the foundations of decision theory offered by Leonard Savage in Savage (1972). Craig Fox and Amos Tversky have, nevertheless, offered an indirect defense of Savage. They provided in Fox and Tversky (1995) an explanation of Ellsberg’s two-color problem (...) in terms of a psychological effect: ambiguity aversion . The ‘comparative ignorance’ hypothesis articulates how this effect works and explains why it is important to an understanding of the typical pattern of responses associated with Ellsberg’s two-color problem. In the first part of this article we challenge Fox and Tversky’s explanation. We present first an experiment that extends Ellsberg’s two-color problem where certain predictions of the comparative ignorance hypothesis are not confirmed. In addition the hypothesis seems unable to explain how the subjects resolve trade-offs between security and expected pay-off when vagueness is present. Ellsberg offered an explanation of the typical behavior elicited by his examples in terms of these trade-offs and in section three we offer a model of Ellsberg’s trade-offs. The model takes seriously the role of imprecise probabilities in explaining Ellsberg’s phenomenon. The so-called three-color problem was also considered in Fox and Tversky (1995). We argue that Fox and Tversky’s analysis of this case breaks a symmetry with their analysis of the two-color problem. We propose a unified treatment of both problems and we present a experiment that confirms our hypothesis. (shrink)

The disjunction effect (Tversky & Shafir, 1992) occurs when decision makers prefer option x (versus y) when knowing that event A occurs and also when knowing that event A does not occur, but they refuse x (or prefer y) when not knowing whether or not A occurs. This form of incoherence violates Savage's (1954) sure-thing principle, one of the basic axioms of the rational theory of decision making. The phenomenon was attributed to a lack of clear reasons for accepting an (...) option (x) when subjects are under uncertainty. Through a pragmatic analysis of the task and a consequent reformulation of it, we show that the effect does not depend on the presence of uncertainty, but on the introduction of non-relevant goals into the text problem, in both the well-known Gamble problem and the Hawaii problem. (shrink)

One reason why humans don't behave according to standard game theoretical rationality is because it's not realistic to assume that everyone else is behaving rationally. An individual is expected to have psychological mechanisms that function to maximize his/her long-term payoffs in a world of potentially “irrational” individuals. Psychological decision theory has to be individualistic because individuals make decisions, not groups.

Decision theory, understood as providing a normative account of rationality in action, is often thought to be an adequate formalization of instrumental reasoning. As a model, there is much to be said for it. However, if decision theory is to adequately account for correct instrumental reasoning, then the axiomatic conditions by which it links preference to action must be normative for choice. That is, a choice must be rationally defective unless it proceeds from a preference set that satisfies the axiomatic (...) conditions. -/- The crucial feature of standard decision theory for present purposes is that it conceives rational action as maximizing, as doing the best that one can in terms of satisfying one’s preferences. For maximizing to be possible, the preference set in question must completely order a person’s options. But I have argued elsewhere that that condition is often unmet by actual preference sets, so maximizing is not always available. Given that it is not, satisficing deserves attention, both as the most important alternative to maximizing and for the lessons it can yield with respect to goal-directed action. With those lessons in hand, standard maximizing decision theory is reconsidered, with the aim of showing that it does not adequately represent the normative distinction between means and ends. (shrink)

Two views of game theory are discussed: (1) game theory as a description of the behavior of rational individuals who recognize each other’s rationality and reasoning abilities, and (2) game theory as an internally consistent recommendation to individuals on how to act in interactive situations. It is shown that the same mathematical tool, namely modal logic, can be used to explicitly model both views.

Does conscious reflection lead to good decision-making? Whereas engaging in reflection is traditionally thought to be the best way to make wise choices, recent psychological evidence undermines the role of reflection in lay and expert judgement. The literature suggests that thinking about reasons does not improve the choices people make, and that experts do not engage in reflection, but base their judgements on intuition, often shaped by extensive previous experience. Can we square the traditional accounts of wisdom with the results (...) of these empirical studies? Should we even attempt to? I shall defend the view that philosophy and cognitive sciences genuinely interact in tackling questions such as whether reflection leads to making wise choices. (shrink)

Our aim in this paper was to establish an empirical evaluation for similarity effects modeled by Rubinstein; Azipurua et al.; Leland; and Sileo. These tests are conducted through a sensitivity analysis of two well-known examples of expected utility (EU) independence violations. We found that subjective similarity reported by respondents was explained very well by objective measures suggested in the similarity literature. The empirical results of this analysis also show that: (1) the likelihood of selection for the riskier choice increases as (...) the pair becomes more similar, (2) these choice patterns are consistent with well-known independence violations of expected utility, and (3) a significant proportion of individuals exhibit intransitive choice patterns predicted under similarity effects, but not allowed under generalized expected utility models for risky choice. (shrink)

In this paper I discuss the problem of providing an account of the normative force of theories of rationality. The theories considered are theories of rational inference, rational belief and rational decision— logic, probability theory and decision theory, respectively. I provide a naturalistic account of the normativity of these theories that is not viciously circular. The account offered does have its limitations though: it delivers a defeasible account of rationality. On this view, theories of rational inference, belief and decision are (...) not a priori . Rather, they are a posteriori and may change over time. Finally, I compare this approach with another that emerges from the Ramsey-Lewis approach to defining theoretical terms. (shrink)

The results generated by experimentalists in psychology and economics haveled to numerous advances in the study of human decision making under risk.Camerer (1995) and Rabin (1998) provide excellent reviews of the relevantliterature. These results clearly display the gap between normative theoriesof ideal behavior and descriptive theories of observed behavior. The mostprominent result is loss aversion – the observation that a loss is given greatervalue than a gain of an equal size – and the resulting S-shaped utility function.Rabin puts the key (...) point as follows: ``Researchers have identified a pervasive feature of reference dependence: In a wide variety of domains, people are significantly more averse to losses than they are attracted to same size gains''(Rabin 1998, 13–14). In what follows, I will show that the ``wide variety of domains'' is wide indeed. In particular, I will review the effects of the S-shaped utility function on the resolution of the decision to commit a crime, to decision to violate professional ethics, and the decision to participate in a rebellion. (shrink)

The present note first discusses the concept of s-convex pain functions in decision theory. Then, the economic behavior of an agent with such a pain function is represented through the comparison of some recursive lotteries.

There is a surprising disconnect between formal rational choice theory and philosophical work on reasons. The one is silent on the role of reasons in rational choices, the other rarely engages with the formal models of decision problems used by social scientists. To bridge this gap, we propose a new, reason-based theory of rational choice. At its core is an account of preference formation, according to which an agent’s preferences are determined by his or her motivating reasons, together with a (...) ‘weighing relation’ between different combinations of reasons. By explaining how someone’s preferences may vary with changes in his or her motivating reasons, our theory illuminates the relationship between deliberation about reasons and rational choices. Although primarily positive, the theory can also help us think about how those preferences and choices ought to respond to normative reasons. (shrink)

Rational choice theory analyzes how an agent can rationally act, given his or her preferences, but says little about where those preferences come from. Instead, preferences are usually assumed to be …xed and exogenously given. We introduce a framework for conceptualizing preference formation and preference change. In our model, an agent’s preferences are based on certain ‘motivationally salient’properties of the alternatives over which the preferences are held. Preferences may change as new properties of the alternatives become salient or previously salient (...) ones cease to be so. We suggest that our approach captures endogenous preferences in various contexts, and helps to illuminate the distinction between formal and substantive concepts of rationality, as well as the role of perception in rational choice. (shrink)

This text is a non-technical overview of modern decision theory. It is intended for university students with no previous acquaintance with the subject, and was primarily written for the participants of a course on risk analysis at Uppsala University in 1994.

This collection brings together the essays of one of the foremost American philosophers of economics. Cumulatively they offer fresh perspectives on foundational questions such as: what sort of science is economics? and how successful can economists be in acquiring knowledge of their subject matter?

Ellsberg (The Quarterly Journal of Economics 75, 643–669 (1961); Risk, Ambiguity and Decision, Garland Publishing (2001)) argued that uncertainty is not reducible to risk. At the center of Ellsberg’s argument lies a thought experiment that has come to be known as the three-color example. It has been observed that a significant number of sophisticated decision makers violate the requirements of subjective expected utility theory when they are confronted with Ellsberg’s three-color example. More generally, such decision makers are in conflict with (...) either the ordering assumption or the independence assumption of subjective expected utility theory. While a clear majority of the theoretical responses to these violations have advocated maintaining ordering while relaxing independence, a persistent minority has advocated abandoning the ordering assumption. The purpose of this paper is to consider a similar dilemma that exists within the context of multiattribute models, where it arises by considering indeterminacy in the weighting of attributes rather than indeterminacy in the determination of probabilities as in Ellsberg’s example. (shrink)

This volume collects four published articles by the late Tamara Horowitz and two unpublished papers on decision theory: "Making Rational Decisions When Preferences Cycle" and the monograph-length "The Backtracking Fallacy." An introduction is provided by editor Joseph Camp. Horowitz preferred to recognize the diversity of rationality, both practical and theoretical rationality. She resisted the temptation to accept simple theories of rationality that are quick to characterize ordinary reasoning as fallacious. This broadly humanist approach to philosophy is exemplified by the articles (...) in this collection. As just one example, in "The Backtracking Fallacy," she argues that there are policies for decision-making a person may adopt if the person prefers to do so, but need not adopt. A person who employs such a policy no longer can regard standard expected utility theory as exceptionless, thereby sacrificing theoretical simplicity. But it is a mistake, Horowitz argues, to preserve theoretical simplicity by falsifying the decision making methods real people really use. (shrink)

This paper reports an experiment which investigates a possible cognitive antecedent of event-splitting effects (ESEs) experimentally observed by Starmer and Sugden (1993) and Humphrey (1995) – the learning of absolute frequency of event category impacting on the learning of probability of event category – and reveals some evidence that it is responsible for observed ESEs. It is also suggested and empirically substantiated that stripped-down prospect theory will accurately predict ESEs in some decision making tasks, but will not perform well in (...) others. This contention, it is argued, is indicative of fundamental descriptive shortcomings in the economic conception of choice under uncertainty and may entail implications beyond the direct concerns of this paper. (shrink)

Many decisions involve multiple stages of choices and events, and these decisions can be represented graphically as decision trees. Optimal decision strategies for decision trees are commonly determined by a backward induction analysis that demands adherence to three fundamental consistency principles: dynamic, consequential, and strategic. Previous research (Busemeyer et al. 2000, J. Exp. Psychol. Gen. 129, 530) found that decision-makers tend to exhibit violations of dynamic and strategic consistency at rates significantly higher than choice inconsistency across various levels of potential (...) reward. The current research extends these findings under new conditions; specifically, it explores the extent to which these principles are violated as a function of the planning horizon length of the decision tree. Results from two experiments suggest that dynamic inconsistency increases as tree length increases; these results are explained within a dynamic approach–avoidance framework. (shrink)

In this article the theoretic evolution and the empirical-experimental efforts that have led to the affirmation of the bounded/procedural rationality paradigm are discussed. Moreover, the debate on supporters of the "optimization" approach and supporters of the "bounded/procedural rationality" approach is traced, highlighting the irreconcilability of these two approaches and, in retort, a solid defense against a merely "reductionist" attempt of the innovative context of the Simonian theory. Critically going over the debate on decision dynamics, it becomes clear how, due to (...) the uncertain nature of rational processes, it is impossible to establish the decision-making best way. The imperfect character of individual choice is explained by how the decider identifies a solution that appears satisfying in that moment due to cognitive and temporal limits. (shrink)

Representation theorems are often taken to provide the foundations for decision theory. First, they are taken to characterize degrees of belief and utilities. Second, they are taken to justify two fundamental rules of rationality: that we should have probabilistic degrees of belief and that we should act as expected utility maximizers. We argue that representation theorems cannot serve either of these foundational purposes, and that recent attempts to defend the foundational importance of representation theorems are unsuccessful. As a result, we (...) should reject these claims, and lay the foundations of decision theory on firmer ground. (shrink)

A rule for the acceptance of scientific hypotheses called 'the principle of cost-benefit dominance' is shown to be more effective and efficient than the well-known principle of the maximization of expected (epistemic) utility. Harvey's defense of his theory of the circulation of blood in animals is examined as a historical paradigm case of a successful defense of a scientific hypothesis and as an implicit application of the cost-benefit dominance rule advocated here. Finally, various concepts of 'dominance' are considered by (...) means of which the effectiveness of our rule may be increased. (shrink)

The classical theory of preference among monetary bets represents people as expected utility maximizers with concave utility functions. Critics of this account often rely on assumptions about preferences over wide ranges of total wealth. We derive a prediction of the theory that bears on bets at any fixed level of wealth, and test the prediction behaviorally. Our results are discrepant with the classical account. Competing theories are also examined in light of our data.

In this paper I examine Don Ross’s application of unificationism as a methodological criterion of theory appraisal in economics and cognitive science. Against Ross’s critique that explanations of the preference reversal phenomenon by the ‘heuristics and biases’ programme is ad hoc or ‘Ptolemaic’, I argue that the compatibility hypothesis, one of the explanations offerd by this programme, is theoretically and empirically well-motivated. A careful examination of this hypothesis suggests several strengths of a procedural approach to modelling cognitive processes underlying individual (...) decision making, compared to a multiple-agent approach which Ross promotes. I argue that the debate between economists and psychologists are both theoretical and empirical, but cannot be resolved by appealing to the ideal of unification. (shrink)

The “exchange paradox”—also referred to in the literature by a variety of other names, notably the “two-envelopes problem”—is notoriously difficult, and experts are not all agreed as to its resolution. Some of the various expressions of the problem are open to more than one interpretation; some are stated in such a way that assumptions are required in order to fill in missing information that is essential to any resolution. In three experiments several versions of the problem were used, in each (...) of which the information given was sufficient to determine an optimal choice strategy when it exists or to justify indifference regarding keeping or trading when such a strategy does not exist. College students who were presented with the various versions of the problem tended to base their choices on simple heuristics and to give little evidence of understanding the probabilistic implications of the differences in the problem statements. (shrink)

The classical theory of preference among monetary bets represents people as expected utility maximizers with concave utility functions. Critics of this account often rely on assumptions about preferences over wide ranges of total wealth. We derive a prediction of the theory that bears on bets at any fixed level of wealth, and test the prediction behaviorally. Our results are discrepant with the classical account. Competing theories are also examined in light of our data.

The objective of this paper is to construct an implementable theory of rational decision-making for cognitive agents subject to realistic resource constraints. It is argued that decision-making should select actions indirectly by selecting plans that prescribe them. It is also argued that although expected values provide the tool for evaluating plans, plans cannot be compared straightforwardly in terms of their expected values, and the objective of a realistic agent cannot be to find optimal plans. The theory of Locally Global planning (...) is proposed as a realistic alternative to standard "maximizing" theories of rational decision-making. (shrink)

This paper investigates decision-theoretic planning in sophisticated autonomous agents operating in environments of real-world complexity. An example might be a planetary rover exploring a largely unknown planet. It is argued th a t existing algorithms for decision-theoretic planning are based on a logically incorrect theory of rational decision making. Plans cannot be evaluated directly in terms of their expected values, because plans can be of different scopes, and they can interact with other previously adopted plans. Furthermore, in the real world, (...) the search for optimal plans is completely intractable. An alternative theory of rational decision making is proposed, called “locally global planning”. (shrink)

The objective of this book is to produce a theory of rational decision making for realistically resource-bounded agents. My interest is not in “What should I do if I were an ideal agent?”, but rather, “What should I do given that I am who I am, with all my actual cognitive limitations?” The book has three parts. Part One addresses the question of where the values come from that agents use in rational decision making. The most comon view among philosophers (...) is that they are based on preferences, but I argue that this is computationally impossible. I propose an alternative theory somewhat reminiscent of Bentham, and explore how human beings actually arrive at values and how they use them in decision making. Part Two investigates the knowledge of probability that is required for decision-theoretic reasoning. I argue that subjective probability makes no sense as applied to realistic agents. I sketch a theory of objective probability to put in its place. Then I use that to define a variety of causal probability and argue that this is the kind of probability presupposed by rational decision making. So what is to be defended is a variety of causal decision theory. Part Three explores how these values and probabilities are to be used in decision making. In chapter eight, it is argued first that actions cannot be evaluated in terms of their expected values as ordinarily defined, because that does not take account of the fact that a cognizer may be unable to perform an action, and may even be unable to try to perform it. An alternative notion of “expected utility” is defined to be used in place of expected values. In chapter nine it is argued that individual actions cannot be the proper objects of decision-theoretic evaluation. We must instead choose plans, and select actions indirectly on the grounds that they are prescribed by the plans we adopt. However, our objective cannot be to find plans with maximal expected utilities. Plans cannot be meaningfully compared in that way.. (shrink)